COVID-19 in South Korea - and potential implications for us (wherever we are)
(Updated: 2020-03-16 10:30:15)
So, I have been watching the epidemic in China and Korea since the beginning, but it is still not easy to settle into this reality here in the US.
First of all, everyone, STAY HEALTHY and see what YOU can do!
Second, there are many excellent articles, especially including this one, but I’m sharing some more questions (see left panel) and data for those who are curious about the situation in Korea specifically. All data are from press release from KCDC - available to the public in both Korean and English. Kudos!
By the way, to understand the Korean context, see below figure from Washington Post.
(Source: Washington Post’s How countries arond the world have tried to contain the coronavirus)
Q 1. When did it start?
On January 20, 2020, there was the first laboratory confirmed COVID case.
Q 2. How fast has it been spreading?
For this question, let’s focus on the number of new cases by day.
For about a month, only 30 cases were confirmed - mostly in/near Seoul. However, starting from the case No. 31 (a super transmitter who was confirmed on February 18), the number of new cases exponentially increased - primarily in Daegu and a region surrounding it but throughout the country. For 10 days, more than 400 new cases were confirmed everyday, with a peak of 909 new cases on February 29. More recently, the number of new cases started to decrease (see below). For the first time since February 22, the number of new cases is below 100 for two days in a row! Still, as of 2020-03-16, a total of 8236 people have been infected.
(Source: KCDC’s daily press release on 2020-03-16)In Daegu, where about three quarters of the cases are concentrated, the daily number of new cases has decreased clearly. Thank God! 
(Source: Figure from KCDC’s daily press release, “Updates on COVID-19 in Korea (as of 15 March)”)
But, COVID can and does continue to spike up. In Seoul, there was a peak around the same time with the sharp epidemic in Daegu, followed by several days with much lower number of or no new cases. But, there seems to be a specific call-center related epidemic, as shown in the sudden increases in the number of new cases around March 11th.
(Source: Figure from KCDC’s daily press release, “Updates on COVID-19 in Korea (as of 14 March)”)
Q 3. What age groups are affected?
For this question, let’s look at the total cumulative number of confirmed cases since the outbreak per 100,000 population by age group, not the absolute number. Also, keep in your mind, this is what we see under a very aggressive track-test-isolate strategy (see this and this). Finally, KCDC releases the number by 10-year age group, and I’m following that categorization.
- Incidence rate is substantially high in the 20s: 34 people have been infected per 100,000 population in their 20s. At least partially, this is reflection of a very concentrated epidemic in Daegu related to a church, and the age pattern among the church attendants. So this age pattern may not be relevant for more generalized pandemic situation.
- Incidence rate among those under 20 is low. It may indicate either children are less susceptible, and/or - more importantly - they have been protected at home since all Korean schools have been in long winter break (typically over several weeks) or under temporary closure since the end of December, 2019.
Q 4. What is mortality - overall and by age groups?
Among those who have COVID, mortality rate among the elderly with COVID is very high: 9.3% for those who are 80 or older, and 5.3% for those who are between 70-79.
Again, this is the case under a very aggressive track-test-isolate strategy, but with no nation wide lock down. As of 2020-03-16, a total of 75 people with COVID have died, 0.9% among all COVID cases. These rates - overall as well as by age group - are lower than mortality rates in China.
There are news articles about extremely over-burdened health systems especially in Daegu. I’ve read at least one mortality case on the newspaper while he/she was waiting for hospital admission, and patients from Daegu and a surrounding province being transferred to other less-affected provinces. However, my impression (as a public health trained reader) is that most severe cases do receive treatment at hospitals. I’m looking for more systematic data on health systems’ capacity and response.
Q 5. How extensive testing has been?
Very aggressive. As of 2020-03-16, a total of 275 thousand people have been tested. There are 51 million people in the country, and 5 in every 1000 people have been test. This is the highest testing rate in the world. Epidemiological investigation of the case No. 31 (who was confirmed on February 18th) prompted immediate and massive testing in Daegu and nation wide.
(Source: KCDC’s daily press release. The number of tests is calculated based on the daily increase in the total number of tests reported.)
More questions and data coming soon, as I continue digging the awesome KCDC website…
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